The present invention relates to anti-static compositions and treatments, and more specifically to a new composition having improved properties as an anti-static agent.
The marked tendency of thermoplastic polymers and other materials to accumulate static charges have prompted study of possible means of eliminating or reducing this property, which may be undesirable for a variety of reasons. For example, dust and other particles for foreign matter adhere more readily to fibers such as those used in making carpeting and clothing materials which carry a static charge. Static discharge or sparks from articles carrying a static charge can be hazardous in explosive atmospheres. Static charges on human hair promote more rapid soiling and other cosmetically undesirable effects. Objectionable features of accumulated static charges are also well known in other circumstances.
Among the attempted approaches to allieviating this problem are the following:
1. Development of more electrically conductive polymers, e.g., tetracyanoquinodimethane.
2. Incorporation of additives which migrate to the surface of the plastic or fiber and modify its electrical properties, examples of these being fatty quaternary ammonium compounds, fatty amines, and phosphate esters; other types of anti-static additives are hygroscopic compounds, such as polyethylene glycols, and hydrophobic slip additives which markedly reduce the coefficient of friction of the plastic.
3. Copolymerization of an anti-static resin with the base polymer.
While all of the foregoing approaches to providing a satisfactory anti-static treatment have met with certain degrees of success, all are limited in some manner in effectiveness and/or inconvenient methods of application. For example, static charges may be prevented from building up on clothing during the drying process by placing specially treated cloths, or the like, in the dryer or by adding chemical solutions to the wash or rinse water; however, no chemical is known to applicant which may be combined with the detergent prior to packaging which will serve to treat the clothing against static buildup as well or better than prior art treatments. Essentially the same is true of carpets; that is, special anti-static sprays, or the like, are available for application after washing and drying, but no anti-static agent is known which may be combined directly with the rug shampoo and will continue in its effectiveness after drying and repeated vacuuming.